1. Field of Technology
The present invention relates to a throttle valve control apparatus for an internal combustion engine, whereby a degree of the throttle valve opening is controlled in accordance with the accelerator pedal actuation.
2. Background Technology
A throttle valve control apparatus is known in the prior art, whereby the actuation position of an accelerator pedal is detected and a throttle valve is driven in accordance with the relationship between the detected actuation position of the accelerator pedal and a predetermined characteristic of the degree of the throttle valve opening. Furthermore, a throttle valve control apparatus is known in the prior art (Japanese Patent Laid-open No. 59-74341) whereby a plurality of different throttle valve opening degree characteristics are stored in a memory as a data map. When one characteristic from among this plurality of opening degree characteristics is selected (by operation of a switch, for example), the throttle valve is driven in accordance with the difference between the accelerator pedal actuation position and the selected throttle valve opening degree characteristic.
With such a prior art throttle valve control apparatus, an appropriate opening degree characteristic can be selected in accordance with the current operating status of the engine, and hence an improved engine performance can be attained. However, since a substantial number of throttle valve opening degree characteristics are necessary in order to cover various different engine operating conditions, a comparatively large amount of memory capacity is required to store the necessary data. This leads to problems of increased manufacturing cost, in spite of recent reductions in memory prices. On the other hand, if only a small number of throttle valve opening degree characteristics are stored in the memory, then the system cannot respond to slight differences between the driving operations of a variety of drivers.